Galileo Galilei was the foremost scientist of his day. Though he never left Italy, his inventions and discoveries were heralded around the world. His telescopes allowed him to reveal the heavens and enforce the astounding argument that the earth moves around the sun. For this belief, he was brought before the Holy Office of the Inquisition, accused of heresy, and forced to spend his last years under house arrest. Galileo's oldest child was thirteen when he placed her in a convent near him in Florence, where she took the most appropriate name of Suor Maria Celeste. Her support was her father's greatest source of strength. Her presence, through letters which Sobel has translated from Italian and masterfully woven into the narrative, graces her father's life now as it did then. Galileo's daughter dramatically recolors the personality and accomplishment of a mythic figure whose seventeenth-century clash with Catholic doctrine continues to define the schism between science and religion.